Sheet metal pin socket



1962 H. E. HENSCHEN 3,058,091

SHEET METAL PIN SOCKET Filed June 4, 1959 5 Sheets-Sheet 1 INVENTOR.HOMER E. HE N BY 0W2), M I f/fi Oct. 9, 1962 H. E. HENSCHEN SHEET METALPIN SOCKET 5 Sheets-Sheet 2 Filed June 4, 1959 Oct. 9, 1962 H. E.HENSCHEN 3,058,091

SHEET METAL PIN SOCKET Filed June 4, 1959 l 5 Sheets-Sheet 5 INVENTOR.HOMER E. HENSCHEN Oct. 9, 1962 Filed June 4, 1959 H. E. 'HENSCHEN SHEETMETAL PIN SOCKET 5 Sheets-Sheet 4 0 M 6 l m I INVENTCSR.

HOMER. E. HENSCHEN Oct. 1952 H. E. HENSCHEN 3,058,091

SHEET METAL PIN SOCKET Filed June 4, 1959 '5 Sheets-Sheet 5- INVENTOR.HOMER E. HENSCHEN 21% M. JW

United States Patent 3,958,091 SHEET METAL PEN SUCKET Homer E. Henschen,Carlisle, Pa., assignor to AMP Incorporated, Harrisburg, Pa. Filed June4, 1959, Ser. No. 818,115 7 Claims. Cl. 339-217) This invention relatesto disengageable pin and socket type electrical connections.

Pin and socket connections of the type known to the art comprise acylindrical pin which is secured, as by crimping, to a first wire and asocket having an axial bore which is secured to the second wire.Disengageable electrical connections of this type are widely used,particularly for relatively small wires, i.e. AWG 16 or smaller, andofier the advantages of compactness and a high degree of reliability.Where a large number of electrical conductors must be disengageablyconnected, it is common practice to mount a plurality of electricalcontact pins in one dielectric block and a corresponding number ofsockets in a similar block so that by bringing together or separatingthe two blocks, the entire group of conductors can be connected anddisconnected. These connector assemblies often contain as many as 50 or100 pins and sockets to permit the disengageable connection of 50 or 100conductors by the manipulation of only the two dielectric blocks inwhich the pins and sockets are mounted.

There are several structural and functional features which are common topractically all good quality pin and socket connectors and which arefrequently required by the users of such connections. For example, it isdesirable that the socket should have a closed entry, i.e. the entranceto the pin-receiving axial bore of the socket should be defined by acontinuous rigid band of surrounding metal rather than by a split band.Where the socket has a closed entry, the possibility of damage, such asmight result from the attempted insertion of an oversized test probe, isminimized and the life of the connection, in terms of the number ofinsertions and removals of the pin, is lengthened. It is also desirablethat the force required to engage and disengage the pin and socket liewithin relatively closely controlled and predetermined limits because,as explained above, pin and socket connector-s are often mounted indielectric blocks with a relatively large number of pins and sockets ineach block. Since the force required to engage and disengage thesemultiple connector blocks is largely determined by the engaging anddisengaging force required for the individual pins and sockets, itfollows that if this engaging force is high, the engaging anddisengaging force required for the blocks will be extremely high andmanual manipulation of the blocks may be impractical. Of course, it isalso essential that the force exerted at the interface of the individualpins and sockets be adequate to establish a relatively low resistanceelectrical connection and since this contact force is dependent upon theengaging force, it follows that unduly low engaging forces can not betolerated. Finally, it should be mentioned that since many pin andsocket type connections are employed with relatively small wires and incircuits where compactness of design is of the highest importance, it isdesirable to maintain minimum dimensions in the pins and socketsconsistent with the attainment of the required physical and electricalproperties.

Most of the commercially available pin and socket connectors aremanufactured by machining barstock using conventional screw machinetechniques which permit close dimensional tolerances and which thereforeyield closely fitting pins and sockets. It is common practice to formthe sockets by axially boring the barstock and cutting or milling a slottherein. For purposes of achieving the contact pressure between aninserted pin and the socket, a cantilever spring is secured to thesocket in a manner such that it extends parallel to, and into, the slotso that the spring is resiliently stressed when the pin is inserted.U.S. Patent 2,716,744 shows one type of machined socket having aseparate spring of this type for imposing the contact pressure betweenthe pin and socket.

In general, these machined pin and socket connectors give good resultsand are highly satisfactory, however, they are relatively expensive ascompared to connectors which are produced by die-stamping anddie-forming of sheet metal stock. Furthermore, these machined pin andsocket connectors cannot be manufactured in strip form, that is in theform of a continuous strip of connectors each joined to the other by thestock metal from which the strip was made. Connectors in strip formoffer an advantage over loose-piece (i.e. individual) connectors in thata wide variety of crimping presses having feeding devices whichautomatically feed terminals in strip form is available so that the costof applying a strip form connector onto a wire is usually less than thecost of applying a loose-piece connector.

It is an object of the present invention to provide an improved pin andsocket electrical connecting device having a high degree of electricaland mechanical reliability. It is a further object to provide pin andsocket type electrical connectors of a type which can be convenientlyproduced by conventional die stamping and forming methods from sheetmetal strip. A further object is to provide a socket having an improvedcontact spring which is formed integrally with the socket at the time ofmanufacture thereby to avoid the problem of assembling a separate springafter manufacture. A further object is to provide an improved pin andsocket connector which can be conveniently manufactured in strip form.

These and other objects are achieved in a preferred embodiment of theinvention in which the socket member comprises a formed elongated stripof metal having a U-shaped portion at one end which is adapted to becrimped onto the end of a wire. The longitudinal edges of the remainderof the strip are bent relatively towards each other and joined together,as by welding or mechanical fastening, to form an axial pin-receivingsocket. Contact pressure for an inserted pin is established by means ofa spring finger which is integral with the socket member and whichextends obliquely of the socket axis towards a slot in the socket. Atongue extends from the mouth of the socket and is reversely bentrearwardly over this finger and then obliquely away from the socket.This tongue serves the dual function of retaining the socket againstaxial movement in a dielectric block and also on its underside serves asa bearing surface and support for the end portion of the spring finger.By virtue of this arrangement, when the pin is inserted the finger isloaded and is stressed in the manner of a cantilever beam which issupported against lateral movement at its free end. The pin member inaccordance with the preferred embodiment is formed in substantially thesame manner as the socket, that is by bending the longitudinal edges ofa metal strip towards each other. The nose portion of this pin, whichfunctions as the electrical contacting portion, is rolled into the formof a cylinder and an intermediate portion is provided from which isstruck a finger similar to the contact spring finger of the socket. Thisfinger on the pin, however, functions as a retainer to lock the pin in adielectric block.

In the drawings:

FIGURE 1 is a perspective view of a socket member in accordance with theinvention;

FIGURE 2 is a side view of the socket member of FIGURE 1;

FIGURE 3 is a view similar to FIGURE 2 but showing the socket memberpositioned in a dielectric block and illustrating the function of theretaining spring;

FIGURE 4 is a view similar to FIGURE 3 but showing the positions of theparts when a mating pin is inserted into the socket;

FIGURE 5 is a cross sectional view showing a complete pin and socket setwith the parts in engagement with each other;

FIGURE 6 is a side view of a connector pin member in accordance with theinvention;

FIGURE 7 is a plan view illustrating the sheet metal blank from whichthe socket member of FIGURE 1 is formed;

FIGURE 8 is a plan view of the sheet metal blank from which the pinmember of FIGURE 6 is formed;

FIGURE 9 is a perspective view of a dielectric block having openings toreceive pins or sockets in accordance with the invention;

FIGURE 10 is a perspective cut away view of a portion of a dielectricblock showing the form of the openings;

FIGURE ll is a view taken along the line 11--11 of FIGURE 5; and

FIGURE 12 is a perspective view of a stamping and forming progressionshowing the manner in which the socket members in strip form aremanufactured.

Referring now to FIGURES l5 a socket member 2 has at one end thereof aninsulation crimp portion 4 and a wire crimp portion 6. When the socketis secured to a wire, the sidewalls of these crimp portions are bentrelatively towards each other and then towards the insulation and thestrands of the electrical conductor to establish an electrical andmechanical connection therewith. A web 8 extends along the top of thesocket, as viewed in FIGURE 1, and sidewalls 10 extend from the sides ofthis web downwardly. These sidewalls curve towards each other in theirlower portions and their edges 12 are bent outwardly so that theirinternal surfaces are in abutting relationship and are welded as shownat 14 to form a stiffening rib which extends axially along the socket.Sidewalls 10 thus define a pin-receiving axial cavity which issemi-cylindrical in its lower portions, as viewed in FIGURE 1, but whichhas substantially parallel and straight sidewalls in its upper portionsadjacent the web. It will be noted in FIGURE 11 that the radius R of thesemi-cylindrical portion is substantially equal to the distance from theweb to the center of the semi-cylindrical portion so that asubstantially cylindrical pin can be inserted into the cavity. The ribformed by the edges 12 has an extension 16 adjacent crimped portion 6which functions as a stop when the socket is inserted into a dielectricblock.

A resilient finger 18 is formed from the intermediate section of web 8by severing this web from the sidewalls along its longitudinal edges andsevering along a line extending transversely across the web adjacent theopen pin-receiving end of the socket. Advantageously, this finger, whichfunctions as a contact spring, does not extend entirely up to andagainst the front portion 9 of the web but a short section of the web ispunched out during the forming so that an appreciable gap is leftbetween the front end 22 of the finger and the web portion 9.Intermediate its ends this finger is bent downwardly at 19 and into thecavity in the socket while its extreme end 22 is reversely bent so thatit extends outwardly beyond the socket.

On each side of finger 18, sidewalls 10 are cut away as shown at 24 andthe edge portions of the sidewalls are bent outwardly to formstabilizing flanges 26. A tongue 28 is integral with the web at thefrontal portion thereof and is reversely bent at 30 so that it extendsrearwardly towards the crimped portion of the socket as shown in FIGURE2. At the end 22 of finger ;18, this tongue slopes downwardly towardsthe axis of the socket and then obliquely away from the axis of thesocket. While the end 22 of the finger and the portion 32 of the tonguemay normally be in contact with each other, as shown in FIGURE 2, as ageneral rule, neither of these parts is stressed to any appreciableextent by the other when the end of tongue 23 is free as shown in FIGURE2. In other words, the finger is substantially in its normal position asshown in FIGURE 2.

Referring now to FIGURES 3, 4, 9 and 10 a preferred type of dielectricblock 34 has parallel faces 35, 37 and a plurality of cavities 36 eachof which is shaped to receive a socket or a pin as described below.Thus, each cavity has a rearward section opening into face 37 (FIG- URE10) of substantially circular cross section excepting for a fiat wall38, an intermediate section of which slopes obliquely towards the axisof the opening. A frusto-conical transition section 44 is providedintermediate the ends of the cavity and extends about halfway around thecavity wall opposite fiat wall 38. This flat wall ends at an abruptshoulder 40 which is disposed on the rearward side of frusto-conicalsurface 44. The right hand portion of the cavity as viewed in FIGURES 3and 11 is of substantially uniform cross section throughout its lengthand has a semi-cylindrical wall 52 adjoining the frusto-conical surfaceand a pair of diametrically opposed ledges 42 on each side of wallsection 52. A pair of flat parallel sidewalls 48 extend from theseledges to a flat wall 46 which extends from shoulder 40. As shown bestin FIGURE 10, sidewalls 48 extend rearwardly beyond shoulder 40 and thendiverge at 49 to define a guide section which aligns the socket duringinsertion.

As shown in FIGURE 9, block 34 may provide extension 39 on its sideshaving openings 41 for the reception of a suitable means for securingtwo blocks together and/or for polarizing the two blocks to ensure thatthey are assembled to each other in proper orientation. For example, itis known to provide pins in some of these openings to ensurepolarization and machine screws and nuts to clamp a pair of blockstogether. It will be understood that blocks of the type shown usuallyare provided with a metallic housing, the block 34 having a shoulder 43for cooperation with such a housing.

To assemble the socket 2 to the dielectric block, it is merely necessaryto insert the socket from the left as viewed in FIGURE 3 thereby tocompress tongue 28 until it passes beyond shoulder 40 at which point ribextension 16 engages the frusto-conical surface 44. The socket can notbe inserted beyond the position shown in FIGURE 3 by reason of thepresence of this surface and it cannot be withdrawn from the openingsince it is held in place by the end of tongue 28. Where removal of thesocket is necessary, it can be accomplished by merely inserting a narrowblade from the right in FIGURE 3 against the upper surface of tongue 28to depress this tongue and permit it to clear shoulder 40.

When a connector pin 54 of the appropriate size is inserted axially intothe cavity as shown in FIGURE 4, the rounded nose portion of this pinengages the underside of finger 18 and pushes it relatively upwardly,insofar as is permitted by tongue 28, so that the profile of this fingerchanges from that of FIGURE 3 to the profile substantially as shown inFIGURE 4. Essentially, this finger can be considered to be a cantileverbeam extending from the body of the connector socket and having its freeend 22 supported against substantial radial movement away from the axisof the socket. Some radial movement of this free end may take place butsuch movement will be limited by the underside of the tongue. The freeend is, however, free to move axially, relative to the socket axis, overthe underside of tongue 28. The amount of such movement will berelatively slight; however, the fact that this end is free to move is animportant factor in maintaining reproducibility of the insertion andextraction force for the pin.

Turning now to FIGURE 6, there is shown a connector pin in accordancewith the invention which is also formed from sheet metal in the samemanner as the socket. The connector pin comprises a cylindrical contactnose portion 54 at one end which is adapted to enter the socket cavity,a frusto-conical transition section 58, and an intermediate portion 59which has a cross-sectional configuration similar to the intermediatesection of the socket. Thus, this intermediate section has asubstantially fiat web 62 from which parallel sidewalls eX- tendadjacent thereto and the sidewalls in turn are curved towards each otherand their edges are outwardly bent at 60 and welded together to form alongitudinal stiffening rib. As with the socket, this rib is enlarged asshown at 61 to form a stop for the purpose of locating the pin in adielectric block. This intermediate section also provides laterallyextending stabilizing fins 64 on each side of the web and the web itselfis severed along its edges and bent outwardly as shown at 66 to form aresilient finger. This finger functions as a retaining spring forretaining the pin in the dielectric block cavity and, like thecorresponding tongue 28 of the socket, it extends rearwardly towards thecrimped portion in order to serve this function. Thus the pin of FIGURE6 differs from the socket in that the retaining spring 66- in the pin isformed from the web while in the socket the retaining spring is formedby means of the tongue which before bending extends axially in front ofthe socket. The lefthand portion of the pin as viewed in FIGURE 6comprises a wire crimp portion 68 of U-shaped cross section having aflat web as with the socket and an insulation support crimp portion 70having a similar cross sectional configuration. These U-shaped ferruleforming portions are crimped onto the end of a wire in the same manneras the corresponding portions of the socket. It will be apparent fromthe drawing that the intermediate and lefthand end portions (the endswhich are secured to the wires) of the socket and of the pin are similarin shape and dimension. By virtue of this similarity, the dielectricblock 34 can accommodate either pins or sockets and this is anadvantageous feature of the invention in that the number of dif ferentparts (i.e. pins, sockets dielectric blocks) which are required for amultiple connector assembly is thereby reduced.

FIGURES 7 and 8 show the punched out sheet metal blanks from whichsockets and pins in accordance with the invention are formed. Thestructural features of these blanks are identified by the same referencenumerals as those used in FIGURES 1-6 in the foregoing description ofthe finished parts, the reference numerals of FIG- URES 7 and 8 beingdifferentiated by prime marks in the interest of clarity. Referring toFIGURE 12, it will be seen that in the preferred method of formingsockets in accordance with the invention, the blanks are stamped fromstrip metal in side-by-side parallel relationship to each other 'witheach blank connected by means of a slug or connecting piece 72 to acarrier strip 74 having evenly spaced perforations 7 6 therein tofacilitate feeding of the strip to an automatic crimping machine. Duringthe successive forming steps for the socket, the blank is cut to formthe finger 18, the finger is bent, the sidewalls are progressivelycurled upwardly, and the tongue 28 is bent downwardly and rearwardly.The blank for the pin member can be formed in substantially the samemanner as is shown in FIGURE 12 excepting that the foreward extension(56' in FIGURE 8) is rolled about the longitudinal axis of the blank toform the cylindrical contact nose of the pin. Advantageously, the end ofthis extension is scalloped so that a substantially hemisphericalleading end on this contact nose results.

A salient overall advantage of the invention is that it permits themanufacture of pin and socket type connectors by die stamping of sheetmetal and connectors manufactured in this manner can be produced morecheaply than by automatic screw machine methods. Furthermore, aspreviously noted, stamped sheet metal connectors can be produced instrip form and strip form connectors can usually be applied to wiresmore easily than loose-piece connectors by reason of the fact that stripconnectors can be automatically fed to the crimping tool or press withrelative ease. However, for a thorough understanding of the instantinvention, there is presented below a discussion of some limitations ofdie stamping processes and a discussion of some of the structuralfeatures of connectors in accordance with the invention which permit themanufacture of pin and socket nectors by die stamping notwithstandingthese limitations.

In general, where metal articles are manufactured by stamping andforming sheet metal, it is recognized that the dimensional tolerancesobtainable are not as close as the tolerances which are obtainable inmachining operations such as are performed in the manufacture of partsby an automatic screw machine. -It is also recognized in the diestamping art that when sheet metal is bent to form a part of aparticular shape, the metal tends to spring back to some extent afterthe work is removed from the bending die. The tendency of the bent metalto spring back usually cannot be completely overcome and it is commonpractice, where a bending operation is to be performed, to bend themetal to a greater degree than is required in the finished part so thatwhen the metal springs back the part will have the desired configurationafter it is removed from the die. The phenomenon of spring back, itmight be mentioned, is a result of the elasticity which remains in adeformed piece of metal after the yield point has been passed. Whilespring back can be controlled to some extent by over bending, it isdifiicult to control within precise limits.

Considering now some features of the connectors, it will be apparentthat the dimensional tolerances of a pin and socket must be such thatthe parts will be engageable and disengageable with relative ease. Atthe same time, the fit of the pin in the socket must be sufficientlysnug and the force exerted at the pin-socket interface must besufficiently high to establish a low resistance electrical connection.In some known types of connections, this problem ofobtaining adequateforces at the pin-socket interface (i.e. adequate pressures) for a goodelectrical connection without an unduly high insertion force for the pinhave been achieved by providing a cantilever spring on the socket whichis flexed by the pin upon insert-ion thereof. These cantilever contactsprings must be designed such that they will withstand the deflection towhich they will be subjected upon insertion of the pin without theimposition of stresses higher than the yield point of the material. Forexample, where the contact portion of the pin has a diameter of about0.050 inch, as a practical matter, the contact spring should be capableof deflecting about 0.004 inch without exceeding its yield point and thecontact spring should impose the desired contact pressure on the pinwhen it is deflected by this amount. It would be impractical to designthe spring for a deflection of less than about 0.004 inch for a 0.050inch diameter pin by reason of the tolerances in the pin diameter forwhich allowances must be made.

In most known connectors which have such cantilever springs, the springhas been provided as a separate piece which is asembled to the connectorby clinching or some similar securing method. This scheme of having thespring as a separate piece has a distinct advantage in that the springcan be made of a metal having better spring properties than theconnector itself. To illustrate, brass or phosphor bronze are excellentmetals for the socket itself since they are easily formed, havesufficiently good electrical conductivity and strength and can becrimped onto wire ends with relative ease. However, these metals are notdesirable spring materials for the cantilever springs of sockets of theinstant type by reason of the fact that their yield strengths are notsufliciently high. The yield strength of phosphor bronze is about 75,000p.s.i. While the yield strength of a hardened brass is about 62,000p.s.i. It would be impractical and difficult to design a simplecantilever spring of relatively thin sheet using these materials whichwould satisfy the performance requirements of cantilever springs forsockets of the instant type. Reference is made to US. Patent to SwansonNo. 2,716,744 for a teaching that it is desirable to make these springsfrom a relatively high yield point material such as berylium copper orInconel (an 80% Ni, Fe, Cr alloy).

-In the present invention, the spring may be formed of a material havinga relatively lower yield strength than in these prior art devices byreason of the fact that this spring is a supported cantilever ratherthan a simple cantilever. The end of the spring normally bears againstthe underside of the tongue or is positioned very close to this tongueand this end is, moreover free to move longitudinally relative to thesurface of the tongue. Thus, when the pin is inserted, the contactspring is flexed in the manner of a cantilever beam which is freelysupported at its end. Recourse to beam stress formulae will show that asupported cantilever beam of a given length and cross section willwithstand a considerably higher load without exceeding its yield pointthan will a similar beam without end support. The beam load in theinstant invention is, of course, the load imposed by a pin and thereaction forces imposed by the spring on the pin to establish theelectrical connection.

A mathematical analysis of an unsupported cantilever beam will show thefollowing relations: For a simple cantilever beam where For a supportedcantilever beam, and assuming the load is applied at a point 0.61 I fromthe fixed end, the load P is as follows:

s bi (H) 10241 The ratio of these loads 1 B PA is then 5.75 so that(III) P =5.75 P

Thus a supported cantilever beam of a given material and givendimensions will withstand a load 5.75 times greater than an identicalunsupported beam assuming that the unsupported beam is loaded at its endand the supported beam is loaded at 0.61 I.

It will be noted from Formula I that P will increase as the length l ofthe beam is reduced and it might seem that a simple cantilever beam ofextremely short length might be employed in order to develop therequired contact pressure P However, as the length of the beam isreduced, its maximum deflection at its end is also reduced and, aspointed out above, the contact spring must be capable of some minimumdeflection as a practical matter to allow for manufacturing tolerancesand variations. Therefore, it would not be a satisfactory solution toreduce the lengths of the contact spring in order to obtain the requiredcontact pressure.

The foregoing discussion is not intended to limit the inventions to theassumptions made or to the formulae presented since these formulae aremerely expressions of 8 the relationships which exist for a particularembodiment of the invention. Where the supported cantilever contactspring is loaded at a point other than 0.61 I, the exact ratiospresented will not obtain. This discussion is merely presented then toshow the advantages in a specific case.

It is not intended to imply that the tongue is completely rigid in thedisclosed embodiment. As shown in the drawings, upon insertion of thepin some fiexurc will be imparted to the tongue via the end of thecontact spring. However, the end of the contact spring is not free tomove radially and since its radial movement is substantially limited, itis stressed in the manner of a supported cantilever in the disclosedembodiment. In some instances it may prove practicable to have a completely rigid support, such as the wall of the dielectric lock, for thecontact spring.

Turning now to the problem of spring back with reference to thedisclosed embodiment, it will be recalled that the dielectric block isadvantageously of molded phenolic or other plastic. Molded plastic partscan be made to very close dimensional tolerances with ease and thedimensions of the openings in the block are, in the disclosedembodiment, held Within precisely predetermined limits. When the socketis inserted into the opening, the end of the tongue is flexed towardsthe socket axis as shown in FIGURES 3 and 4 so that after insertion,this tongue occupies a precisely predetermined position with relation tothe location of the contact spring.

From the foregoing it will be apparent that the precise dimensions ofthe openings in the block are utilized as a means for compensating forany lack of precision in the position of the tongue. This means that theexact location of the tongue, as fixed in the bending die duringmanufacture of the socket, is not of paramount importance and theproblem of bending this tongue in a precise and exacting manner isobviated. Of course, as explained above, precise bending of the tonguewould be difficult because of the spring back of the metal.

Another advantageous feature of the invention is that since the contactspring is integral with the connector (i.e. formed to the same strip)the contact surface between the spring and the pin is fully effective asan electrically conducting interface. Where, as in the prior art, thespring is a separate piece, its contact with the tongue is not fullyeffective because an additional interface, or electrical barrier, ispresented Where the contact spring is mechanically secured to thesocket.

Changes in construction will occur to those skilled in the art andvarious apparently different modifications and embodiments may be madewithout departing from the scope of the invention. The matter set forthin the foregoing description and accompanying drawings is offered by wayof illustration only. The actual scope of the invention is intended tobe defined in the following claims when viewed in their properperspective against the prior art.

I claim:

1. A sheet metal electrical connecting device formed from an elongatedstrip having an end portion of U-shaped cross section crimpable onto aconductor and a tubular adjoining portion, the longitudinal edges ofsaid strip in said tubular adjoining portion being radially outwardlybent and secured together to form an axially extending rib, said ribbeing of stepped profile to form a stop intermediate its ends forengagement with a portion of a housing member into which said connectingdevice is adapted to be inserted, a spring extending lengthwise of saidconnector struck out from said tubular adjoining portion on the oppositeside from said rib, and longitudinal stabilizing ears on each side ofsaid spring, said ears comprising outwardly bent portions of said stripadjacent to said spring, said ears being adapted to engage complementarysurfaces in said housing thereby to prevent movement of said connectingdevice.

2. A device as set forth in claim 1 wherein said tubular adjoiningportion comprises a socket for reception of a pin, said springcomprising a contact spring for engagement with said pin upon insertionthereof.

3. A device as set forth in claim 1 wherein said tubular adjoiningportion comprises a socket for reception of a pin, said springcomprising a contact spring for engagement with said pin, said springextending towards the open pin receiving end of said socket and havingan intermediate incurvate portion extending into the interior of saidtubular portion whereby said spring is displaced relatively outwardly ofsaid socket by said pin.

4. A device as set forth in claim 1 wherein said tubular adjoiningportion comprises a socket for reception of a pin, said springcomprising a contact spring for engagement with said pin, a tongueextending from the open end of said tubular portion rearwardly of saidtubular portion and past said spring, said tongue being adapted toengage a shoulder in said housing member to prevent withdrawal of saidconnecting device therefrom, and said tongue functioning as a supportfor the end of said spring upon insertion of said pin.

5. A device as set forth in claim 1 including a cylindrical pin portionextending from said tubular portion, said spring extending towards saidU-shaped section and obliquely away from the axis of said tubularportion whereby, said spring functions as a retainer spring to preventwithdrawal of said connecting device from said housing.

6. A sheet metal electrical connecting device formed from an elongatedstrip having an end portion of U-shaped cross section crimpable onto aconductor and a tubular adjoining portion, said tubular portioncomprising a socket adapted to receive a pin, the longitudinal edges ofsaid strip in said tubular portion being radially outwardly bent andsecured together to form an axially extending rib, said rib being ofstepped profile to form a stop intermediate its ends for engagement witha portion of a housing member into which said connecting device isadapted to be inserted, a spring extending lengthwise of said tubularportion towards the pin-receiving end thereof, said spring having anintermediate incurvate portion extending into the interior of saidtubular portion whereby said spring imposes a contact pressure on saidpin, a tongue extending from the open end of said tubular portionrearwardly thereof and past said spring, said tongue being adapted toengage a shoulder in said housing member to prevent withdrawal of saidconnecting device therefrom, said tongue functioning as a support forthe end of said spring upon insertion of said pin, and longitudinalstabilizing ears on each side of said spring, said ears comprisingoutwardly bent portions of said strip adjacent to said spring, said earsbeing adapted to engage complementary surfaces in said housing therebyto prevent movement of said connecting device.

7. A sheet metal electrical connecting device formed from an elongatedstrip, said connecting device comprising a cylindrical tubular portionadapted to receive a pin, a spring struck out from said tubular portionand extending lengthwise thereof, said spring having an intermediateincurvate portion extending into the interior of said tubular portionwhereby said spring imposes a contact pressure on said pin, a tongueextending from the open end of said tubular portion rearwardly thereofand past said spring, said tongue being adapted to engage a shoulder ina housing member into which said device is adapted to be insertedthereby to prevent withdrawal of said device from said housing, anintermediate portion of said tongue functioning as a support for the endof said spring, and longitudinal stabilizing ears on each side of saidspring, said ears comprising outwardly bent portions of said stripadjacent to said spring, said ears being adapted to engage complementarysurfaces in said housing thereby to prevent movement of said connectingdevice.

References Cited in the file of this patent UNITED STATES PATENTS2,310,142 Woodman Feb. 2, 1943 2,701,350 Soreng Feb. 1, 1955 2,738,485Batcheller Mar. 13, 1956 2,794,963 Hess et a1 June 4, 1957 2,813,257Cornell Nov. 12, 1957 2,888,662 Hammell May 26, 1959 FOREIGN PATENTS1,188,936 France Mar. 16, 1959

